1. Field of the Invention
The present invention is related to interconnect busses of computer systems and in particular to isochronous transactions across such interconnect busses.
2. Description of the Related Art
Many computer systems utilize an interconnect bus for multiple types of traffic. One type of traffic is isochronous traffic. Isochronous traffic is time dependent traffic that requires a certain bandwidth. In addition, isochronous traffic can require a certain minimum payload size per transaction. One example of isochronous traffic is a video signal, which needs to ensure that data is delivered at least as fast as it needs to be displayed, to avoid jerkiness and other similar display problems. Another example of isochronous traffic is an audio signal that is synchronized with a video signal. Conventional interconnect bus architectures have not been optimal for isochronous traffic.
A number of techniques have been employed to provide isochronous traffic on a shared bus. However, these techniques have focused on the interconnect traffic without considering either the requester or the completer of such traffic. Further, these techniques have typically depended on the good behavior of the requester, and typically fail to prevent ill-behaved requesters from using more than the allocated bandwidth.